There is an increasing interest in magnetic particles because of their wide application in such fields as biotechnology, biomedical, electromagnetics, magnetic storage and coating to name just a few. Various approaches to the preparation of magnetic particles have been investigated including co-precipitation of ferrous and ferric salts under alkaline conditions in the presence of either polymers or surfactants, crosslinking of functional polymer in an emulsifier-stabilized magnetic nanoparticle dispersion and layer-by-layer (LBL) self-assembly of alternating layers of polyelectrolytes and magnetic nanoparticles onto colloidal templates.
Despite of the success of these, and other, approaches in preparing the magnetic particles, there are still some major drawbacks with respect to the methods and the properties of the particles produced. For example, synthesis involves tedious multiple step reactions and the use of large amounts of toxic solvent agents, emulsifiers and surfactants. Leaching of magnetic nanoparticles from the polymeric particles and nanoparticle dissolution in acidic medium are still serious concerns. In addition, magnetic polymeric particles produced through these approaches generally have broad size distributions and usually lack of surface functional groups, which are highly desirable for further chemical modifications.